How to store previously selected values in array set in Configuration.

Summary:

In Config,I have 2 text attributes(Country and State)and one Array set(2 columns,Select(Boolean),City(text)),And I enter values in to these text attributes(Consider India,Telangana),On action click Array set should filter the relevant city(Hyderabad),i select this option then change search with US,Texas which will return Dallas in the arrayset and i select this option as well. Now when i remove the filter(blank values in my 2 text attributes) and search it should return me array of selected values which is [Hyderabad,Dallas].In recommendation rule,Have tried using jsonarrayappend function to store previously selected value but it is returning me only latest selection but not previous one